Method for decolorization of waste water
US5180497A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 11, 1991 |
| Grant date | Jan 19, 1993 |
| Priority date | — |
| Expiry date | Sep 11, 2011 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S210/917
- WIPO fieldEnvironmental technology
- WIPO sectorChemistry
Abstract
A method for the decolorization of waste water containing coloring matters comprising dyestuff and/or pigment, in which PVA is added to a waste water containing coloring matters as above mentioned so as to catch the coloring matters in the waste water into the PVA, a precipitant of the coloring matters is added to the resultant waste water so as to render the coloring matters absorbed onto the PVA insoluble, a coagulant of PVA is added to the waste water so as to make the PVA insoluble, and then the thus insolubilized PVA containing the coloring matters is separated for the recovery thereof, and thus the decolorization of a waste water containing the coloring matters can be done skillfully and economically by eliminating the drawbacks in the conventional arts.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.